Many good comments about waiting for 1K miles, but to me, my needs became quickly obvious. Backrest, simply makes long rides more comfortable. If you feel the bike is "darty" or leans too much, there is a reason the Baja Ron Sway Bar is often mentioned, it makes a world of difference. I hated mine without it, and I had a 2018 RTL, so I know the nuances of Spyder Riding. I put the SlingMods lower front light (mentioned earlier) on because I caught it on sale, and you can't argue with visibility for a cheap price. I put a Carpuride screen on mine because I use Android Auto; if you can catch them on sale they're fairly cheap and work well, but mounts cost nearly as much as the device. If you travel a lot, bags are nice and really help. One not mentioned: I came from riding motorcycles since I was 14 years old, and I missed a handbrake. I added the ISCI handbrake, and while VERY expensive and requiring much more pull than a normal handbrake, I find it really helpful and easy to grab. Not a necessity though, unless you have some hip/knee issue that makes you nervous with just the foot brake.
Of all, I put the sway bar on with less than 150 miles, it was a huge improvement!
